Facebook moved quickly this week to assure users they are still in control of the information they post to the popular social networking site. But the company did not say it would make any changes in its Terms of Service (TOS) agreement at the heart of the current controversy.

At issue are changes Facebook made a few weeks ago to its TOS, the online contract users agree to in order to join community sites such as Facebook. In a Feb. 16 blog post headlined, "Facebook: All Your Stuff is Ours, Even if You Quit," the Consumerist Web site noted what it called "a seemingly slight but very important (and disturbing) change in Facebook's terms of service regarding user-generated content."

The changes are allowed as part of Facebook's standard TOS, which says in part: "We reserve the right to change our Privacy Policy and our Terms of Use at any time."

The post from the Consumerist (a not-for-profit subsidiary of Consumers Union) noted one stipulation of the TOS in particular that led, presumably, to the response Monday by Facebook CEO Mark Zuckerberg: The TOS notes that users grant Facebook "an irrevocable, perpetual, non-exclusive, transferable, fully paid, worldwide license" to use, adapt and distribute "any User Content you (i) Post on or in connection with the Facebook Service."

In a blog post Monday afternoon headlined, "On Facebook People Own and Control Their Information," Zuckerberg said that "A number of people have raised questions about our changes" and that he wanted to clarify what was done to the TOS.

In the best interest of users?

Zuckerberg argued that the changes were actually made in users' best interests.

"Our philosophy is that people own their information and control who they share it with," he wrote. "When a person shares information on Facebook, they first need to grant Facebook a license to use that information so that we can show it to the other people they've asked us to share it with. Without this license, we couldn't help people share that information."

"In reality, we wouldn't share your information in a way you wouldn't want," he added.

Facebook is hardly alone in having to deal with controversy over how it handles user's personal information and files. Other sites, including Google, have had their own share of privacy-related issues.

Like Facebook, Google has sought to assure users that whatever the potential risk to privacy its policies may appear to have, it operates in its user's best interests. Google has said it's guided by the credo "Do no evil."

But privacy advocates continue to lobby against the increasing amount of personal information being collected and for user's to have more legal control of how that information is used.

It's not the first run-in Facebook has had with users over privacy concerns, however. The site's controversial Beacon service automatically placed ads in members profiles based on their activities -- and became a lightning rod for criticism in 2007. Facebook ultimately apologized and pulled the service in response to users' outcry, but the product still resulted in a pair of class-action lawsuits.